Unformatted text preview: Section: Lab #2 – Water and Solute Movement Through Cell Membranes Date: 9/19/2012 Just type in your names below Quiz Total* Post- lab Partner 1 Name: Katie Kenney ______ /10 ______ /10 Partner 2 Name: Thaddeus Babiec ______ /10 ______ /10 ______ /10 ______ /10 Partner 3 Name: Table 1 Table 1: Effects of Tonicity on Flux of Water 2 NaCl (mM) 0 50 Water 5 4.75 NaCl 0 0.25 3 100 4.5 0.5 4 5 150 Tube
1 4.25 4 200 0.75 1 *Blood 0.5 0.5 0.5 0.5 0.5 Table 2 Table 2: Group Data of Hemolysis Rate of Different Solutes Solution Hemolysis Time (60 sec max) 5 8.9 60 Prop Alc Urea Ribose Table 3 Table 3: Class Data of Hemolysis Rate of Different Solutes Solution
Group 1 Prop Alc Urea Ribose 7 3 60 Group 3 5 4.5 60 Group 4 4 5 60 Group 5 5 8.9 60 Group 6 8 5 60 Group 7 3 4.9 60 Group 8 5 8 60 Group 9 3 3 60 Group 2 Clear or Cloudy? clear clear cloudy cloudy cloudy Group 10 5 2 60 Group 11 8 6 60 Group 12 4 2 60 Average 5.181818182 4.754545455 60 Standard
Error 0.536286589 0.679620701 0 Prop Alc vs
t-test 0.313647404 Prop Alc vs Ribose
9.83761E-17 Urea vs
9.69976E-16 Figure 1 70 60 Time (sec) 50 40 Series1 30 20 10 0 1 2 3 Solutes Questions 1.1 When the solution is clear, the RBC have hemolyzed. When the solution is cloudy, the RBC have not hemolyzed. When a cell in this experiment hemolyzes and the solution turns clear, it means that water flowed into the cell to accommodate a higher concentration of solute inside the cell and the cell burst. If the solution remains cloudy, this means that water flowed out of the cell towards a higher concentration of solute outside if the cell. The NaCl did not cross over the membrane in either direction because it is a non- penetrating solute. 1.2 The solutions that turned clear were hypotonic to the RBC, and the solutions that were cloudy were hypertonic to the RBC. The concentrations of 0mM and 50 mM of NaCl were both hypotonic, 150mM and 200mM of NaCl were both hypertonic, and 100mM of NaCl was isotonic. We can say this one is isotonic, meaning equal concentrations of NaCl inside and outside of the cell, because the solution remained cloudy, which means that it did not hemolyze and is therefore not hypotonic. Because the concentration of the tube with 100 mM of NaCl was in the middle of the hypotonic and hypertonic concentrations, it can be assumed that this one is isotonic. 2.1 It would be expected that the solutes with the smallest molecular weight, in this case urea and propanol, would have the fastest hemolysis rate, and the solute with higher molecular weight, ribose, would take longer to get through the membrane because of its size, therefore having a slower hemolysis rate. The results did follow these expectations. 2.2 It would be expected that the least polar solute, propanol, would have the fastest hemolysis rate because it can move through the membrane through simple diffusion, when the more polar molecules, urea and ribose, need to go through specific channels because of their polarity. In general, these assumptions proved true in both our data and the class data. 3.1 The two tests that had significantly different hemolysis rates were n- propanol vs. ribose and urea vs. ribose. 3.2 It would be expected that propanol would have the fastest hemolysis rate because it has the smallest molecular weight out of the three solutes, and it is the least polar of the three solutes. This did not follow our predictions and urea was in fact the fastest hemolysis molecule with propanol a close second. ...
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